1. Field of the Invention
This invention relates to a testing method in an information system having storage (data storage devices) shared by a plurality of servers, in which loads and errors are generated in the storage to conduct tests, and also relates to an information system performing such tests.
2. Description of the Related Art
In recent years, there have been an increasing number of examples of information systems constructed from a plurality of servers and a plurality of storage products, with the object of streamlining operations or providing services to customers. Examples include business systems which perform sales processing, order processing and financial processing, and service delivery systems which deliver web contents. In such information systems, various tests are often performed, including performance tests to accumulate information relating to performance of the information system and operation tests to verify the operation of the information system, in order to judge whether the system meets the requirements demanded of the user introducing the information system.
In such tests, often errors or loads are caused in storages. For example, as performance tests, usage rate, response time or other parameters of resources, such as the CPU or memory in servers or the disks in the storages may be measured when loads are generated in the storages, and as operation tests, errors may be caused in storage devices to verify whether processing can be continued by the information system using only storage devices in which errors have not occurred (which are normal).
In the past, mechanisms to generate storage loads and errors have been incorporated into either servers or storages. For example, when the generation mechanism is realized in a computer program, the program must be installed in the server; the program will differ for each server OS (operating system), vendor of the storage equipment, and host bus adapter (equipment on the server side functioning as an interface with the storage equipment) used.
When the above generation mechanism is realized in hardware, when for example the generation mechanism is incorporated into a host bus adapter (HBA), either the firmware of the HBA must be rewritten, or an HBA with firmware functioning as the generation mechanism must be newly installed. When incorporating the above generation mechanism in storage, either the firmware of the controller which controls storage must be rewritten, or the controller must be replaced with a controller equipped with firmware to function as a generation mechanism. As conventional technology, a method has been disclosed to generate pseudo-traffic in order to evaluate network performance using dummy loads (see for example Japanese Patent Laid-open No. 2000-252987).
However, because in conventional testing methods the mechanism to generate loads and errors is incorporated in servers or storages, there are the following problems. First, when the mechanism to generate loads or errors is realized in a program, processing of the program consumes the server CPU, memory and other resources for original processing to attain the original objectives for which the information system was introduced (for example, if a business system, execution of business applications; of a service delivery system to deliver web content, then web server applications). So they are in race contention and a different situation is simulated from a situation in which loads and errors generate when the above original processing is actually performed.
Secondly, when the above generation mechanism is realized in a program, a variety of different programs must be prepared according to differences in OSes, different storage equipment vendors, differences in HBAs used, and similar, so that considerable labor and time are required to install the programs on individual servers and to make program settings after installation. Third, when the above generation mechanism is realized in hardware, considerable time and labor are again required for installation of the hardware and to make settings after the installation.